Waste water, surface water, storm water, ground water and sea water are frequently contaminated with the fecal material of man or other animals. Cryptosporidium oocysts (protozoan infections), E. coli and Vibrio cholerae (bacterial infections), and Hepatitis A (viral infections) are but a few examples. Water filtration and water purification are required in many situations. In addition, these waters may include colloidal materials, which can destroy expensive Reversed Osmosis (“RO”) membranes used in water purification and particularly in desalinization. The fouling of these expensive membranes must be prevented by pretreatment of water scheduled to undergo reversed osmosis treatment.
Ultrafiltration (“UF”) can be used, for example, for production of tertiary effluent from secondary effluent in municipal waste water treatment plant, such as for “polishing” sand filter tertiary effluent and, for example, for water pretreatment in reversed osmosis applications such as the desalination of sea water and brackish water. Ultrafiltration is a separation process using filter membranes having pore sizes in the range of 0.1 micron (100 nanometer) to 0.001 micron (1 nanometer). UF membranes are used to treat surface water, storm water, ground water, seawater and waste water as either primary treatment or as pretreatment in reversed osmosis desalination plants, or other types of desalinization plants. In these and other applications, UF filters are used in water filtration to remove high molecular-weight substances, colloidal materials, organic and inorganic polymeric molecules, and pathogens.
However, UF water filters are expensive.
Large water treatment plants typically use 500-1000 UF filters at a cost of many millions of dollars (including support systems). One such filter typically costs more than a thousand dollars. For example, at retail prices current at the time of filing of this application, Applied Membrane Model M-UB8040PES 8″×40″ UF PES Membrane 10,000 MWCO (Molecular Weight Cut Off) costs is $1544 (without the pressure tank). Hydronautics' Hydrocap UF filter sells for $2550.
Apart from the UF membranes per se, water filtration apparatus typically requires various tubes and couplings (e.g. quick release) as used in the industry or described in publications such as DE 8612396, JP 2007195851, U.S. Pat. No. 4,923,226, US 2009/227954, DE 29803673, or WO 2007/049053.